The present invention relates to an apparatus for foam removal. More specifically, the present invention relates to an apparatus which requires no outside source of energy for removing excess foam in any type of vessel by forcing it through a screen, causing it to collapse and hence revert to a liquid, and carrying it off in a trough.
Heretofore, numerous devices have been employed in foam removal. Generally, they relate to abating surface tension such as through the utilization of an electrical charge, overflow weirs, skimming devices which mechanically remove foam, use of pumps which suck in the foam and discharge it usually in the form of a liquid, and chemical treatment compounds. However, all of these various conventional methods, matters and techniques, as well as others not listed, generally involve the use of some outside source of energy.
An exception is the apparatus of U.S. Pat. No. 1,893,411, granted Jan. 3, 1933. This patent relates to the removal of foam or the "head" obtained in the fermentation of liquor utilizing a floating plate having apertures therein. As the foam passes through the apertures, some of it will collapse and return to the tank. In another embodiment of the invention, truncated cones extend upwardly out of the plate with other parts of the plate containing small apertures. The foam passes through the cones and accumulates on the plate until it is naturally broken down over a period of time and returns as liquid to the tank through the small plate apertures. Generally, this apparatus is incapable of handling moderate or large amounts of generated foam and does not provide for foam removal, but rather returns it to the tank.
A prior art patent which relates to the utilization of a pump for foam removal is U.S. Pat. No. 3,169,841, granted Feb. 16, 1975. Basically, the apparatus is merely a suction pump having flexible veins therein which are driven by an offset shaft in a cylindrical chamber. The pump, through a vacuum, sucks foam into a chamber and the chamber is reduced in volume, thereby exerting pressure on the foam and causing it to collapse and form a liquid which is discharged.
In U.S. Pat. No. 3,722,184 granted Mar. 27, 1973, a liquid foam mixture is pumped through a series of baffles or foam-breaking pads which causes the bubbles to collapse or become increasingly smaller. Here, again, the foam is not removed, but rather remains within the same vessel. Additionally, large amounts of foam cannot be readily handled.